An individual who approaches someone's desk or workstation in a work environment almost immediately after sending them an email, usually to confirm that the email has been received.

Bill: I just sent you an email. Did you get it?
Mike: Probably, I haven't checked.
Bill: Can you check?
Mike: Uh yeah, looks like I got it.
Bill: Thoughts?
Mike: My immediate thoughts are you're an email courier and a douchebag.

An individual who gets up from their chair at their desk to walk to someone else's desk to announce the contents of the email, verbatim. Completely replacing the need for any automated email 'you've got mail' alert , or the email at all for that matter.

Dave: "Kristen, I just sent you an email to let you know to switch the address in the document and to take out the comma before the word 'and' in the second line of the second paragraph on the third page."

Kristen: "For the love of god, please just email it to me and stay in your chair. There is no need to be a email courier, the send button and the internet do that for you. "